Abstract: Temperature distribution on steady state without disturbance in density lock is simulated ex-perimentally in this paper,and the temperature stratification end point is discovered on the temperature curve on steady state.It separated the heat conduction layer and homoiothermy layer.Only when the temperaturestratification end point is in the density lock,heat can be restrained effectually.The temperature field is simulated with three methods.The first one is a method of semi-infinite flat-panel heat conduction,the second one is a method of one dimensional steady state conduction in constant cross-section straight-fin,and the last one is calculated using Fluent calculation software.The results indicated that the method of semi-infinite flat-panel heat conduction is the best one to calculate the distribution of temperature and location of temperature stratification end point.